Conventional wisdom holds that Raman spectroscopy is a technique suited to the analysis of moderate-to-high concentration materials in solid or liquid form. Raman scattering is such a weak effect that one needs to be analyzing a high concentration analyte in order for the signal to be measurable over the inherent noise of other material in which it might be embedded, or the inherent fluorescence background noise of the instrument itself, particularly in the case of fiber-coupled Raman probes. Accordingly, Raman has not generally been considered an appropriate analytical technique for low-concentration “trace” elements in solids or liquids, or particularly for measuring gasses in just about any meaningful concentration, let alone trace levels. While certain trace concentration measurements have been made, they have been with direct-coupled Raman equipment, not industrial-compatible fiber-coupled instrumentation.